Daily activity helps protect against cancer

So if being active decreases your cancer risk, will being inactive increase your risk? A new field of research into sedentary behavior is offering some compelling evidence.

A recent study from the American Institute for Cancer Research found that taking one- to two-minute breaks every hour can reduce some common indicators of cancer risk, such as waist circumference, insulin resistance and inflammation. Sitting for long periods affects those biomarkers, regardless of body weight or regular daily exercise.

“The new factor in this study is the notion of needing to stay active throughout the day,” says Dale Shepard, MD, PhD, an oncologist and clinical researcher at Cleveland Clinic’s Taussig Cancer Institute. “A lot of studies have looked at exercise ‘periods’ that may reduce the risk of recurrence or the ability to tolerate therapy better. This study examines not so much the benefits of exercise in preventing cancer, but the risks associated with not exercising and being sedentary for hours at a time.”

Research studies

Every year more than 90,000 cases of breast cancer and colon cancer are linked to physical inactivity. Research shows that increased physical activity reduces overall risk by 25 to 30 percent for breast and colon cancers, 30 to 35 percent for endometrial cancer and 10 to 20 percent for prostate cancer.

A recent study involved measuring C-reactive protein, a marker of inflammation, which is linked to cancer risk. It showed that moderate to vigorous daily activity reduced the C-reactive protein levels in postmenopausal women. Though scientists still are working to understand how inflammation affects cancer risk, they do know that immune cells activated by inflammation release elements that damage DNA and produce cell mutations.

Added benefits

“Someone who is in pretty good shape and does develop cancer will be able tolerate therapy and treatment more easily than someone who doesn’t exercise regularly,” says Dr. Shepard. “Another benefit is that being more active usually leads to other healthy habits.”

Cancer survivors also should be aware of how much time throughout the day they are sedentary. In addition to increased cancer risk, sedentary behavior is linked to diabetes and cardiovascular disease, which become primary concerns for survivors.

The bottom line

“It doesn’t have to be meaningful activity or a robust workout every hour,” says Dr. Shepard. “The goal is to break that sedentary period throughout the day, in addition to a dedicated cardiovascular workout.”